Okazaki, Reiji

Reiji Okazaki showed that when replicating E. coli are labelled for short periods of time with precursors of DNA, some of the newly synthesized DNA is recovered as small fragments of 100-200 nucleotides long, which are subsequently incorporated into double-stranded DNA. 

This dilemma was resolved by Reiji Okazaki, who found that a significant proportion of newly synthesized DNA exists as small fragments. These units of about a thousand nucleotides (called Okazaki fragments) are present briefly in the vicinity of the replication fork (Figure 28.21). 

The bidirectional synthesis of DNA implies that one strand is synthesized in the 5 —> 3 direction and the other in the 3 —> 5 direction. However, all known enzymes that synthesize DNA do so in the 5 —> 3 direction. How did Reiji Okazaki explain this paradox ... 

Okazaki fragments Short DNA segments generated during discontinuous replication of the lagging strand these were described by Reiji Okazaki, based on experiments using radioactive deoxynucleotides as precursors in DNA synthesis. 

DNA fragments separated by the nicks are called Okazaki fragments after their discoverer, Reiji Okazaki (Figure 11.11). 

The evidence obtained with electron micrography and other techniques pointed to the fact that this was not the case. Both the strands were replicated together. This perplexing situation was addressed by Reiji Okazaki in 1968. 

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